Challenges of cleaning up waste at a Cumbria nuclear site are "unprecedented" and more complex than "any other operational or decommissioning nuclear site in the world", the head of the team overseeing Sellafield nuclear site.
NMP chairman Tom Zarges dodged claims costs were spiralling out of control and said the consortium was focused on building on "our experience of the last five years".
The challenges at Sellafield are unprecedented, with complexities exceeding any other operational or decommissioning nuclear site in the world, therefore demanding extraordinary technology and skills.
The first term of our contract has been characterised by many successes but also a number of disappointments and areas for improvement.
Our job now is to build on our experience of the last five years to safely and reliably deliver our customer's mission, while further accelerating the pace of change and providing value for money to the NDA, Government and the UK taxpayer.
Sellafield Ltd can confirm that the radioactivity detected by one of our in-air monitors overnight is not attributable to any issue or problem with any of our operations on site.
Our in-air monitors are extremely sensitive and pick up on any abnormality. Overnight the monitoring system initially indicated elevated levels of activity. Following investigation and analysis, we can now confirm these levels to be naturally occurring background radon.
Professor Richard Wakeford, professor of epidemiology at the University of Manchester, has said that the level of radioactivity detected at Sellafield is not above that "encountered in everyday life".
From the information currently available, it appears that an elevated level of radioactivity has been detected at the north of the site, but that it is at a low level above normal.
Such a level would not pose a risk to health that is more than encountered in everyday life, but until the cause of this increase has been identified, for example, what type of radioactive materials are responsible, the Sellafield management have told non-essential staff not to come into work.
– Professor Richard Wakeford, University of Manchester